/* Internal definitions for FS-Cache
   *
   * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
   * Written by David Howells (dhowells@redhat.com)
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
   * as published by the Free Software Foundation; either version
   * 2 of the License, or (at your option) any later version.
   */
  
  /*
   * Lock order, in the order in which multiple locks should be obtained:
   * - fscache_addremove_sem
   * - cookie->lock
   * - cookie->parent->lock
   * - cache->object_list_lock
   * - object->lock
   * - object->parent->lock

   * - cookie->stores_lock

   * - fscache_thread_lock
   *
   */
  
  #include <linux/fscache-cache.h>
  #include <linux/sched.h>
  
  #define FSCACHE_MIN_THREADS	4
  #define FSCACHE_MAX_THREADS	32
  
  /*

   * cache.c

   */
  extern struct list_head fscache_cache_list;
  extern struct rw_semaphore fscache_addremove_sem;
  
  extern struct fscache_cache *fscache_select_cache_for_object(
  	struct fscache_cookie *);
  
  /*

   * cookie.c

   */
  extern struct kmem_cache *fscache_cookie_jar;
  
  extern void fscache_cookie_init_once(void *);
  extern void __fscache_cookie_put(struct fscache_cookie *);
  
  /*

   * fsdef.c

   */
  extern struct fscache_cookie fscache_fsdef_index;
  extern struct fscache_cookie_def fscache_fsdef_netfs_def;
  
  /*

   * histogram.c

   */
  #ifdef CONFIG_FSCACHE_HISTOGRAM
  extern atomic_t fscache_obj_instantiate_histogram[HZ];
  extern atomic_t fscache_objs_histogram[HZ];
  extern atomic_t fscache_ops_histogram[HZ];
  extern atomic_t fscache_retrieval_delay_histogram[HZ];
  extern atomic_t fscache_retrieval_histogram[HZ];
  
  static inline void fscache_hist(atomic_t histogram[], unsigned long start_jif)
  {
  	unsigned long jif = jiffies - start_jif;
  	if (jif >= HZ)
  		jif = HZ - 1;
  	atomic_inc(&histogram[jif]);
  }
  
  extern const struct file_operations fscache_histogram_fops;
  
  #else
  #define fscache_hist(hist, start_jif) do {} while (0)
  #endif
  
  /*

   * main.c

   */
  extern unsigned fscache_defer_lookup;
  extern unsigned fscache_defer_create;
  extern unsigned fscache_debug;
  extern struct kobject *fscache_root;

  extern struct workqueue_struct *fscache_object_wq;

  extern struct workqueue_struct *fscache_op_wq;

  DECLARE_PER_CPU(wait_queue_head_t, fscache_object_cong_wait);
  
  static inline bool fscache_object_congested(void)
  {
  	return workqueue_congested(WORK_CPU_UNBOUND, fscache_object_wq);
  }

  extern int fscache_wait_bit(void *);
  extern int fscache_wait_bit_interruptible(void *);

  /*

   * object.c

   */

  extern const char fscache_object_states_short[FSCACHE_OBJECT__NSTATES][5];

  extern void fscache_withdrawing_object(struct fscache_cache *,
  				       struct fscache_object *);
  extern void fscache_enqueue_object(struct fscache_object *);
  
  /*

   * object-list.c
   */
  #ifdef CONFIG_FSCACHE_OBJECT_LIST
  extern const struct file_operations fscache_objlist_fops;
  
  extern void fscache_objlist_add(struct fscache_object *);
  #else
  #define fscache_objlist_add(object) do {} while(0)
  #endif
  
  /*

   * operation.c

   */

  extern int fscache_submit_exclusive_op(struct fscache_object *,
  				       struct fscache_operation *);
  extern int fscache_submit_op(struct fscache_object *,
  			     struct fscache_operation *);

  extern int fscache_cancel_op(struct fscache_operation *);

  extern void fscache_abort_object(struct fscache_object *);
  extern void fscache_start_operations(struct fscache_object *);
  extern void fscache_operation_gc(struct work_struct *);

  
  /*

   * proc.c

   */
  #ifdef CONFIG_PROC_FS
  extern int __init fscache_proc_init(void);
  extern void fscache_proc_cleanup(void);
  #else
  #define fscache_proc_init()	(0)
  #define fscache_proc_cleanup()	do {} while (0)
  #endif
  
  /*

   * stats.c

   */
  #ifdef CONFIG_FSCACHE_STATS
  extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS];
  extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS];
  
  extern atomic_t fscache_n_op_pend;
  extern atomic_t fscache_n_op_run;
  extern atomic_t fscache_n_op_enqueue;
  extern atomic_t fscache_n_op_deferred_release;
  extern atomic_t fscache_n_op_release;
  extern atomic_t fscache_n_op_gc;

  extern atomic_t fscache_n_op_cancelled;

  extern atomic_t fscache_n_op_rejected;

  
  extern atomic_t fscache_n_attr_changed;
  extern atomic_t fscache_n_attr_changed_ok;
  extern atomic_t fscache_n_attr_changed_nobufs;
  extern atomic_t fscache_n_attr_changed_nomem;
  extern atomic_t fscache_n_attr_changed_calls;
  
  extern atomic_t fscache_n_allocs;
  extern atomic_t fscache_n_allocs_ok;
  extern atomic_t fscache_n_allocs_wait;
  extern atomic_t fscache_n_allocs_nobufs;

  extern atomic_t fscache_n_allocs_intr;

  extern atomic_t fscache_n_allocs_object_dead;

  extern atomic_t fscache_n_alloc_ops;
  extern atomic_t fscache_n_alloc_op_waits;
  
  extern atomic_t fscache_n_retrievals;
  extern atomic_t fscache_n_retrievals_ok;
  extern atomic_t fscache_n_retrievals_wait;
  extern atomic_t fscache_n_retrievals_nodata;
  extern atomic_t fscache_n_retrievals_nobufs;
  extern atomic_t fscache_n_retrievals_intr;
  extern atomic_t fscache_n_retrievals_nomem;

  extern atomic_t fscache_n_retrievals_object_dead;

  extern atomic_t fscache_n_retrieval_ops;
  extern atomic_t fscache_n_retrieval_op_waits;
  
  extern atomic_t fscache_n_stores;
  extern atomic_t fscache_n_stores_ok;
  extern atomic_t fscache_n_stores_again;
  extern atomic_t fscache_n_stores_nobufs;
  extern atomic_t fscache_n_stores_oom;
  extern atomic_t fscache_n_store_ops;
  extern atomic_t fscache_n_store_calls;

  extern atomic_t fscache_n_store_pages;
  extern atomic_t fscache_n_store_radix_deletes;
  extern atomic_t fscache_n_store_pages_over_limit;

  extern atomic_t fscache_n_store_vmscan_not_storing;
  extern atomic_t fscache_n_store_vmscan_gone;
  extern atomic_t fscache_n_store_vmscan_busy;
  extern atomic_t fscache_n_store_vmscan_cancelled;

  extern atomic_t fscache_n_marks;
  extern atomic_t fscache_n_uncaches;
  
  extern atomic_t fscache_n_acquires;
  extern atomic_t fscache_n_acquires_null;
  extern atomic_t fscache_n_acquires_no_cache;
  extern atomic_t fscache_n_acquires_ok;
  extern atomic_t fscache_n_acquires_nobufs;
  extern atomic_t fscache_n_acquires_oom;
  
  extern atomic_t fscache_n_updates;
  extern atomic_t fscache_n_updates_null;
  extern atomic_t fscache_n_updates_run;
  
  extern atomic_t fscache_n_relinquishes;
  extern atomic_t fscache_n_relinquishes_null;
  extern atomic_t fscache_n_relinquishes_waitcrt;

  extern atomic_t fscache_n_relinquishes_retire;

  
  extern atomic_t fscache_n_cookie_index;
  extern atomic_t fscache_n_cookie_data;
  extern atomic_t fscache_n_cookie_special;
  
  extern atomic_t fscache_n_object_alloc;
  extern atomic_t fscache_n_object_no_alloc;
  extern atomic_t fscache_n_object_lookups;
  extern atomic_t fscache_n_object_lookups_negative;
  extern atomic_t fscache_n_object_lookups_positive;

  extern atomic_t fscache_n_object_lookups_timed_out;

  extern atomic_t fscache_n_object_created;
  extern atomic_t fscache_n_object_avail;
  extern atomic_t fscache_n_object_dead;
  
  extern atomic_t fscache_n_checkaux_none;
  extern atomic_t fscache_n_checkaux_okay;
  extern atomic_t fscache_n_checkaux_update;
  extern atomic_t fscache_n_checkaux_obsolete;

  extern atomic_t fscache_n_cop_alloc_object;
  extern atomic_t fscache_n_cop_lookup_object;
  extern atomic_t fscache_n_cop_lookup_complete;
  extern atomic_t fscache_n_cop_grab_object;
  extern atomic_t fscache_n_cop_update_object;
  extern atomic_t fscache_n_cop_drop_object;
  extern atomic_t fscache_n_cop_put_object;
  extern atomic_t fscache_n_cop_sync_cache;
  extern atomic_t fscache_n_cop_attr_changed;
  extern atomic_t fscache_n_cop_read_or_alloc_page;
  extern atomic_t fscache_n_cop_read_or_alloc_pages;
  extern atomic_t fscache_n_cop_allocate_page;
  extern atomic_t fscache_n_cop_allocate_pages;
  extern atomic_t fscache_n_cop_write_page;
  extern atomic_t fscache_n_cop_uncache_page;
  extern atomic_t fscache_n_cop_dissociate_pages;

  static inline void fscache_stat(atomic_t *stat)
  {
  	atomic_inc(stat);
  }

  static inline void fscache_stat_d(atomic_t *stat)
  {
  	atomic_dec(stat);
  }

  #define __fscache_stat(stat) (stat)

  extern const struct file_operations fscache_stats_fops;
  #else

  #define __fscache_stat(stat) (NULL)

  #define fscache_stat(stat) do {} while (0)

  #define fscache_stat_d(stat) do {} while (0)

  #endif

  /*
   * raise an event on an object
   * - if the event is not masked for that object, then the object is
   *   queued for attention by the thread pool.
   */
  static inline void fscache_raise_event(struct fscache_object *object,
  				       unsigned event)
  {

  	if (!test_and_set_bit(event, &object->events) &&
  	    test_bit(event, &object->event_mask))
  		fscache_enqueue_object(object);
  }
  
  /*
   * drop a reference to a cookie
   */
  static inline void fscache_cookie_put(struct fscache_cookie *cookie)
  {
  	BUG_ON(atomic_read(&cookie->usage) <= 0);
  	if (atomic_dec_and_test(&cookie->usage))
  		__fscache_cookie_put(cookie);

  }

  /*
   * get an extra reference to a netfs retrieval context
   */
  static inline
  void *fscache_get_context(struct fscache_cookie *cookie, void *context)
  {
  	if (cookie->def->get_context)
  		cookie->def->get_context(cookie->netfs_data, context);
  	return context;
  }
  
  /*
   * release a reference to a netfs retrieval context
   */
  static inline
  void fscache_put_context(struct fscache_cookie *cookie, void *context)
  {
  	if (cookie->def->put_context)
  		cookie->def->put_context(cookie->netfs_data, context);
  }

  /*****************************************************************************/
  /*
   * debug tracing
   */
  #define dbgprintk(FMT, ...) \
  	printk(KERN_DEBUG "[%-6.6s] "FMT"
  ", current->comm, ##__VA_ARGS__)

  #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
  #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
  #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)

  #define kjournal(FMT, ...) no_printk(FMT, ##__VA_ARGS__)

  
  #ifdef __KDEBUG
  #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
  #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
  #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
  
  #elif defined(CONFIG_FSCACHE_DEBUG)
  #define _enter(FMT, ...)			\
  do {						\
  	if (__do_kdebug(ENTER))			\
  		kenter(FMT, ##__VA_ARGS__);	\
  } while (0)
  
  #define _leave(FMT, ...)			\
  do {						\
  	if (__do_kdebug(LEAVE))			\
  		kleave(FMT, ##__VA_ARGS__);	\
  } while (0)
  
  #define _debug(FMT, ...)			\
  do {						\
  	if (__do_kdebug(DEBUG))			\
  		kdebug(FMT, ##__VA_ARGS__);	\
  } while (0)
  
  #else

  #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
  #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
  #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)

  #endif
  
  /*
   * determine whether a particular optional debugging point should be logged
   * - we need to go through three steps to persuade cpp to correctly join the
   *   shorthand in FSCACHE_DEBUG_LEVEL with its prefix
   */
  #define ____do_kdebug(LEVEL, POINT) \
  	unlikely((fscache_debug & \
  		  (FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
  #define ___do_kdebug(LEVEL, POINT) \
  	____do_kdebug(LEVEL, POINT)
  #define __do_kdebug(POINT) \
  	___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
  
  #define FSCACHE_DEBUG_CACHE	0
  #define FSCACHE_DEBUG_COOKIE	1
  #define FSCACHE_DEBUG_PAGE	2
  #define FSCACHE_DEBUG_OPERATION	3
  
  #define FSCACHE_POINT_ENTER	1
  #define FSCACHE_POINT_LEAVE	2
  #define FSCACHE_POINT_DEBUG	4
  
  #ifndef FSCACHE_DEBUG_LEVEL
  #define FSCACHE_DEBUG_LEVEL CACHE
  #endif
  
  /*
   * assertions
   */
  #if 1 /* defined(__KDEBUGALL) */
  
  #define ASSERT(X)							\
  do {									\
  	if (unlikely(!(X))) {						\
  		printk(KERN_ERR "
  ");					\
  		printk(KERN_ERR "FS-Cache: Assertion failed
  ");	\
  		BUG();							\
  	}								\
  } while (0)
  
  #define ASSERTCMP(X, OP, Y)						\
  do {									\
  	if (unlikely(!((X) OP (Y)))) {					\
  		printk(KERN_ERR "
  ");					\
  		printk(KERN_ERR "FS-Cache: Assertion failed
  ");	\
  		printk(KERN_ERR "%lx " #OP " %lx is false
  ",		\
  		       (unsigned long)(X), (unsigned long)(Y));		\
  		BUG();							\
  	}								\
  } while (0)
  
  #define ASSERTIF(C, X)							\
  do {									\
  	if (unlikely((C) && !(X))) {					\
  		printk(KERN_ERR "
  ");					\
  		printk(KERN_ERR "FS-Cache: Assertion failed
  ");	\
  		BUG();							\
  	}								\
  } while (0)
  
  #define ASSERTIFCMP(C, X, OP, Y)					\
  do {									\
  	if (unlikely((C) && !((X) OP (Y)))) {				\
  		printk(KERN_ERR "
  ");					\
  		printk(KERN_ERR "FS-Cache: Assertion failed
  ");	\
  		printk(KERN_ERR "%lx " #OP " %lx is false
  ",		\
  		       (unsigned long)(X), (unsigned long)(Y));		\
  		BUG();							\
  	}								\
  } while (0)
  
  #else
  
  #define ASSERT(X)			do {} while (0)
  #define ASSERTCMP(X, OP, Y)		do {} while (0)
  #define ASSERTIF(C, X)			do {} while (0)
  #define ASSERTIFCMP(C, X, OP, Y)	do {} while (0)
  
  #endif /* assert or not */